libqos/ahci: Add ahci_port_select helper

This helper identifies which port of the
AHCI HBA has a device we may run tests on.
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1423158090-25580-2-git-send-email-jsnow@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

tests/ahci-test.c

@@ -662,7 +662,7 @@ static void ahci_test_identify(AHCIQState *ahci)
     RegH2DFIS fis;
     AHCICommand cmd;
     PRD prd;
-    uint32_t ports, reg, table, data_ptr;
+    uint32_t reg, table, data_ptr;
     uint16_t buff[256];
     unsigned i;
     int rc;
@@ -684,22 +684,7 @@ static void ahci_test_identify(AHCIQState *ahci)
      */
 
     /* Pick the first implemented and running port */
-    ports = ahci_rreg(ahci, AHCI_PI);
-    for (i = 0; i < 32; ports >>= 1, ++i) {
-        if (ports == 0) {
-            i = 32;
-        }
-
-        if (!(ports & 0x01)) {
-            continue;
-        }
-
-        reg = ahci_px_rreg(ahci, i, AHCI_PX_CMD);
-        if (BITSET(reg, AHCI_PX_CMD_ST)) {
-            break;
-        }
-    }
-    g_assert_cmphex(i, <, 32);
+    i = ahci_port_select(ahci);
     g_test_message("Selected port %u for test", i);
 
     /* Clear out this port's interrupts (ignore the init register d2h fis) */

tests/libqos/ahci.c

@@ -267,3 +267,30 @@ void ahci_hba_enable(AHCIQState *ahci)
      * In the future, a small test-case to inspect the Register D2H FIS
      * and clear the initial interrupts might be good. */
 }
+
+/**
+ * Pick the first implemented and running port
+ */
+unsigned ahci_port_select(AHCIQState *ahci)
+{
+    uint32_t ports, reg;
+    unsigned i;
+
+    ports = ahci_rreg(ahci, AHCI_PI);
+    for (i = 0; i < 32; ports >>= 1, ++i) {
+        if (ports == 0) {
+            i = 32;
+        }
+
+        if (!(ports & 0x01)) {
+            continue;
+        }
+
+        reg = ahci_px_rreg(ahci, i, AHCI_PX_CMD);
+        if (BITSET(reg, AHCI_PX_CMD_ST)) {
+            break;
+        }
+    }
+    g_assert(i < 32);
+    return i;
+}

tests/libqos/ahci.h

@@ -431,5 +431,6 @@ void free_ahci_device(QPCIDevice *dev);
 void ahci_pci_enable(AHCIQState *ahci);
 void start_ahci_device(AHCIQState *ahci);
 void ahci_hba_enable(AHCIQState *ahci);
+unsigned ahci_port_select(AHCIQState *ahci);
 
 #endif